The publication of a report can make for a road-crash, but as the Eddington Transport Study launched into the world yesterday, with the government at least, it looked set for plain sailing. Adair Turner only got his recommendations for pensions adopted after virtually daring the chancellor to rubbish them. Sir Rod Eddington, by contrast, was so confident that his report would go down well at the Treasury that he published it in the same format used for budget documents. But the hard-headed, utilitarian approach that ensured Treasury officials are happy could also lead to difficulties in selling the Eddington agenda more widely.

Whether in economic terms or those of quality of life, there is no doubt that the increasingly clogged arteries of Britain's transport system are taking their toll. Sir Rod explained that if car journey times could be cut by just one tenth in urban areas, then productivity would rise by 1%. Without action, the situation will get worse, with the prospect of the average time wasted each year in traffic hitting four days a year within a couple of decades. Yet despite the huge scale of the problem, the report warned against grand solutions. For the problem is not deemed to be the basic shape of Britain's transport infrastructure, which it is suggested is the right one, but the pressure imposed on particular points within it. Clean-sheet solutions are therefore rejected in favour of prosaic, incremental easing of bottlenecks - extra carriages on trains rather than new west coast mainlines. Rail enthusiasts, in particular, are likely to be disappointed, but, with the spending review set to be eyewateringly tight, it is essential that the biggest possible bang for each buck is extracted.

A second practical implication of the recommendations is likely to prove even more controversial. Although it was not highlighted yesterday, the small print of the report suggests a rebalancing of effort towards London and the south-east, and therefore away from other parts of Britain. Indeed, of the dozens of investments suggested as priority, just one is in Scotland and none is in Wales, a picture which may damp the enthusiasm of a chancellor who remains as Scottish as he is ferrous. Eddington's remit was narrowly economic, and to boost aggregate GDP this prioritisation is probably right. After all, policies that seek to engineer where prosperity occurs, rather than encouraging it where it arises, are rarely the most efficient. But in responding to the report, the government will need to show appreciation of wider issues. For one thing, there is the politics of the congestion charging that Sir Rod quite rightly recommends. Persuading voters to pay for road use they have long enjoyed without charge will hardly be easy; it will be even tougher, though, if many voters see no local improvement in transport infrastructure. And then there are social objectives, such as tackling geographical isolation, which must be balanced carefully against the economics.

On the environment, Eddington is overly technocratic, as seen in controversial proposals to take the final say over planning away from elected ministers. The economic case for new road building and the construction of a new Heathrow runway may well be strong, but many would be left baffled by the government pressing ahead on both counts while it also claims to care about climate change. Sir Rod suggests the circle can be squared because even if, as he recommends, all transport pays the full cost of the carbon it produces, new roads and runways would still be required. His logic is not wrong, but it ignores the role of symbolism in an arena where it is necessary not only to change the relative costs of different actions, but also, through real culture change, to alter people's preferences and habits. The report is founded on sound economics, but ministers would do well to recall that the fate of policies is rarely settled by economics alone.